Apparatus for forming and vulcanizing rubber articles.



N. W. McLEOD. APPARATUS FOR FORMING AND VULCANIZING RUBBER ARTICLES.

Patented Jan. 23, 1917.

APPLICATION FILED MAY 4. I916.

2 SHEETS-SHEET I- if ra rt r' V To all whomz't may concern:

1 UNITED STATES PATENT ome NELSON W. MoLEOD, OF ST. LOUIS, MISSOURI, ASSIGNOR TO AMERICAN MOTORS TIRE COMPANY, OF DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN.

Be it known that I, NELSON W. MoLEon, a citizen of the United States of America, a resident of the city of St. Louis, State of Missouri, have invented certain new and useful Improvements in Apparatus for Forming .and Vulcanizing Rubber Articles, oi which the following is a full, clear, and exact description, reference being had to the accompanying drawings, forming a part of this specification. I

My invention relates to a vulcanizing apparatus providing for the use of internal fluid pressure within a mold and against the rubber article to be vulcanized, in order that such article'may be expanded uniformly in toto and held at every point against the internal wall of the mold during the period of vulcanization. Vulcanizing apparatus of this kind are especially useful in vulcanizing hollow rubber tires such as pneumatic tires or'casings for automobiles.

Numerous efiorts have heretofore;: been made to provide a vulcanizing apparatus using fluid pressure for'the distention of the rubberarticles in the-vulcanizing molds, the originators ofsuch apparatus proposing to utilize fluid agents of various natures, for example, steam or air, or water whichwill be turned to steam when heated within the rubber articles. The use of fluids of these mentioned kinds is objectionable for different reasons, principally because they-permeate the structure to be vulcanized, consequently the prior apparatus have not proven thoroughly satisfactory from a commercial standpoint. i

The object of the presentinvention is to provide a vulcanizin apparatus whichper- '40 mits of the use of a solute hydraulic pressure against the rubber articles being vulcanized, without any-liability of thewater made use of for the hydraulic pressure being converted into steam, and with avoidance of the presence of air in conjunction with the hydraulic pressure medium within the rubber article being vulcanized. Water alone is the ideal substance-foruse as a pressure medium in an apparatus of this kind and it is a well known fact that the presence of steam or air in conjunction-with water as medium to aflord internal pressure within rubber articles to be vulcanized is objection- Specification of Letters Iatent. Application filed may 4,

VUIJOANIZING RUBBER ARTICLES.

H Patented 1916. Serial N0.95,337-

able owing to permeation thereby into the rubber articles and to the inability of. transferring heat with through solid bodies and gaseous bodies.

Difliculty has been experienced in discovering a way of maintaining a strict 'hydraulic pressure within the. rubber articles "to be vulcanized, so that permeation'would beavoided and the'conductivityof the internal fluid pressure medium would be constantly uniform at all points. I

My present invention consists in a con-' struction whereby I eliminate air'from the ulterior-of the rubber-article to be vulcanan. 23, 1917.- l

relative uniformity i'zed and afiord no opportunity for the gen f eration of steam within the rubber articles 7 as will hereinafter appear.

Figure I is a vertical section through my vulcanizingapparatus.- Fig. II is a horizontal section taken on line IIII, Fig. I. Fig. III is a enlarged crosssection through one of the molds and the air vent device mounted therein. Fig. IV is an enlarged cross section through one of the molds, showing an. unvulcanized tire therein as it appears prior tofthe introduction of hy-p draulic pressure into the tire.

In the drawings, I have illustrated my apparatus of preferredconstruction, with the article to be treated shown as rubber tires,

designated A, the tireshaving two edges at their inner circles and being built up of fabric-and rubber compound, in accordance with the usual .practice'in making hollow tires of the pneumatic tire .type. The tires "A are incased within suitable sectional molds 13', each mold including, in addition to shell sections, an abutment ring-5,; which is situated between the edges at the inner circle of the the when the built up raw tire is placed within the mold, to remain in such position throughout the treatment of the tire. The abutment ring, by itspositionbetweenthe edges of the tire, permits of the tire edges being tightly cla'mped between said abut-" 'ment ring and the shell sections of the mold 2 and 2 one of which serves to admit live steam to the pot and the other of which allows the steam to escape from the pot.

The vulcanizer pot has a closure 3, which 5 may be held in closed position by any suitable means, access to the pot being permitted by moving, either the body of the pot or the closure relative to the other part of the pot.

, The vulcanizer pot is-arranged to receive an 10 abutment spider 4 beneath which the molds B are confined as will be presently pointed out. This abutment spider is preferably in the form of a cross and portions of it are positioned beneath lugs 1- extending in- 5 wardly from the wall of the vulcanizer pot at its upper end.

5 designates a mold moving means in the form of a hydraulic ram provided with a head or table 6, the latter being situated 20 within the vulcanizer pot and being movable therein. The ram head 6 serves as a support for the molds B, and upon the movement of the ram and its head toward the opposing abutment spider 4 inserted after 2:, the molds have been put in place, the pressure exerted upon the sectional molds B causes the tires therein to be clamped within the molds between the mold sections and the abutment ring I) to such degree as to render an the joints of the mold fluid tight. Steam admitted into the vulcanizer pot is, therefore, excluded from the molds, except through means to be hereinafter described. The hydraulic'ram 5 is operable in a cylinder 7, into which water or other fluid is in troduced. I

I next come to a description of. the means by which'fluids are conducted into the molds B, for the purpose of first fully expanding and compressing raw tires in saidmolds'and, thereafter, vulcanizing the interior portions of the tires, while theexterior portions of the' tires are being vulcanized from heat transmitted through the mold shells. It

will, however, facilitate the description to A first describe an automatic valve device C,

by which communication is established between the interiors of each mold and the vulcanizer pot to vent air from the tire within the mold prior to the delivery of water thereinto. This valve device C comprises a tube 8 which extends through the abutment ring I) of the mold, the said tube being provided at its inner end with a pipe 9 extending upwardly therefrom in the mold cavity so that its upper end terminates in proximity to the inner face of the tire A, the pipe 9 having in its wall, near its upper end, apertures 10 which provide for the entrance of air from the interior pipe into the tire at the greatest elevation therein. At the outer end of the tube 8 is a valve casing 11,

- containing a valve chamber 13 in which is a valve seat 12 and an air relief valve movable 85 to and from said seat.

The abutment rings 6 of the molds B used in my vulcanizing apparatus contains a duct 1) through which water may be introduced into the tire A within the mold.

14: designates a water conducting pipe provided with as many connections 14* as there are molds, said connections being of such construction as to permit of the ready application of the connections to the abutment rings of the molds at the ducts b. Water is delivered to the water conducting pipe 14 from a hose or other pipe (not shown) which may be detachably connected to a coupling extension 15 of the water conducting pipe in which is a shut off valve 16.

17 designates an expansion chamber attached to and in communication with the water conducting pipe 1 1. This chamber is closed throughout except for the communication with the pipe ll and it may be of the 35 semicircular form shown or any other suit able form. The said expansion chamber is preferably located above the molds as shown in the drawings.

In the practical use of my tire forming and vulcanizing apparatus for the treatment of tires composed of rubber compound and fabric, I proceed as follows :The tires having been built up in the usual manner are placed in the molds B while the rubber compound is in the raw oruncured state, the abutment rings 1) of the molds being positioned between the edges of the tires so that fluid tight joints at such edges are produced. When the abutment rings 1) are put in place they contain the automatic air relief devices C having the check valve 13 which is normally open.

The number of filled molds it is desired to use in the apparatus are placed one upon another with the lowermost mold resting upon the ram head 6. The abutment spider 4 is then inserted into the vulcanizer pot above the molds and in engagement with the lugs 1, thereby locking said abutment spider in such manner as to cause it to constitute astop above the molds.- The ram 5 is then elevated and the molds become clamped between the ram head and the abutment spider 4. The water conducting pipe 14 is then attached to the abutment rings 12 of the several molds B by fitting the connections 14 to said abutment rings and the expansion 7 chamber 17 being attached to said. water conducting pipe the apparatus is in condition 2 for delivery ofhydraulic pressure into the tires within the molds.

A water delivery pipe- (not shown) is attached to the coupling 15 of the water conducting pipe 14 and the shut-off valve 16 being open water is forced into the tires within the molds. As the water enters the tires the air therein escapes through the automatic" valve'devices C, it being understood that the vulcanizer pot is open at this introduced into thetires of the molds -B a certain quantity of the waterenters the exv 4 The tlreshavmg ized to produce steam but the increase in.-

owing to the closure. 3 absent the body of the. pot. When the raw tires are first placed in the molds they do not 1 completely fill the mold cavities owing to such cavities being larger than the raw tires "fas illustrated. in Fig. IV. a The pressure under which the water is introduced intothe tires is preferably one of a degree suiiiciently high to expand the tires to the walls of the mold cavities; although a pressure slightly less than this'may be suficient'for the reason that the-hydraulic pressure in the tires will" be increased whenthe water is heated by the hzeating'of the vulcanizerpot .in the manner t'o'be hereinafter explained. When water is pension-chamber '17, but inasmuch as this ex-'- sure thereagainst.

been filled with water to a subject them to a desired degree of hydraulic pressure-the shut-0E valve 16 is then closed and the water-delivery pipe' is. disconnected from the conducting pipe'extension 15. The

- closure 3 is then secured to the body of the vulcanizer pot and the apparatus is in condition in'the pot heats the molds B and the tires therein while said tires remain J subjected to constant uniform hydraulic pres- 40 v conducting pipe 14 leading thereto becomes sure. As thewater in the tires and in the heated it will naturally expand and become eater in volume. However, in view of the et that the air in the expansion chamber is under pressure, the water will not be vaporvolume of water will be taken care of in: the

- expansion chamber.

In the use of my'vulcanizing apparatus-I preferably introduce steam into the vulcan izing pot at a temperature of about 270 throughout thefpe'riod of vulcanization of the tires in the molds-B. Thewater is introducedinto the tires 'at preferably about 150 be greater or less as'found desirable.

pounds pressure, although this pressure may The expansion chamber, or air chamber 17, is preferably a non-yielding device, the" air trapped in said-'chamber serving as a cushion that may pension. chamberis a closed receptacle the. air therein cannot escape from said chamber,- and is compressed dueto thehydraulic pres v inlet pipe 2 and; escaping therefrom through the outlet'pipe 2". Thesteam in its'circulabe compressed in' response. to the expansion of the water.

Iclaim:- 1. Inan apparatus for vulcanizing rubber articles, a mold, means for introducingvwater into said mold,'- means for heatingthe water in said mold, anda non-yielding expansion device associated with said mold to permit" the expansion of water in the mold without I permitting the generation of steam the 2. In an apparatus for vulcalbizing" rubber articles, a mold, means for introducing water into said mold, means for heating the water in said mold, and a non-yielding expansion I .device'includingan air chamber associated with said mold to permit the expansionlof water in the mold without permitting generation of'steam in the mold. a

3. In an apparatus for vulcanizin'grubber articles, a mold, means for introducing water in said mold, nd a non-yieldingexpansion device including a closed air chamber having communication with the interior of said mold.v T

the

' A. In. an. apparatus for vulcanizing rubber articles,ia mold, means for introducing water into said mold, means for heating theswater, in said mold, and an expansion, chamber "above the plane of said mold having com munication with the interior of the I mold.'

,5. In an apparatus for vulcanizing rubber v in said-mold, and an expansion device in cluding anair chamber locatedlabove the:

plane of. the v water .in the mold and having communication with f the interior of the mold. f K

6, In an apparatus for vulcanizing hollow rubber tires, a tire mold, means for introduc- 7 articles, a, mold, means for introducing water into-said mold, means .for heatingithe water ing water into the tire confined in the mold,=

allow the hollow tire to be filled with water, meansfofiheating the water'in the tire, and

. anon-yielding expansion device including .an air chamber communicating with-the in-- ,terior of the mold to provide for the expan sion of the water in the tire'.'

7. In anapparatus for vulcanizing hollow a venting device associated with said partsto 1 10. rubber tires, ati're' mold, a 'j conductor. through which'watermaybe introduced into;

the tire confined in said,mold,'a ventingde vice associated with said parts to allow the tire to be filled with water, means for" closing the water receiving elements to maintain the tire full of water during'the. vulcanizing op eration, means for heatmg the water in the tire, and a" non-yieldingair chamberjpermit .,-ting the expansion ofiwater 1n the tire.

into said mold, means for heating the water 

